Sources
| Ref. # | Source |
|---|---|
| 1 | Geoff Topp's Postcard Collection |
| 2 | Source unknown |
| 3 | By courtesy of Mersey Docks and Harbour Board |
| 4 | By courtesy of the National Library of Scotland |
| 5 | Original diagram by Brian Watson |
| 6 | From Royal Atlas of England and Wales (1898) |